Executive Summary
Pillar 2: Feedstock Policy outlines strategies to harness the potential for a stable flow of feedstocks to the anaerobic digestion (AD) industry to realise its potential to mitigate climate change, replace fossil fuels, enhance soil quality and productivity, and improve health and sanitation. Feedstocks are the foundation of the industry. With the world currently recycling only 2% of the 105 billion tonnes of organic waste produced each year, there is immense potential for the industry to grow and create a positive impact on the world around it. This pillar outlines concrete actions that policymakers can adopt to address the growing issue of waste management globally and repurpose waste into renewable energy, biofertiliser and other valuable co-products to make a meaningful impact on their communities and the environment.
Primary feedstocks for the biogas industry include the organic fraction of municipal solid waste (food and garden waste), domestic sewage, industrial waste and wastewater (such as effluents from breweries, slaughterhouses, palm oil mills, sugar and ethanol mills and many others), livestock manure and slurries, crop residues and purpose-grown crops. Given the varied sources of feedstocks and the fact that many are not currently collected or segregated, there is a need for streamlining policies and incentives to capture and manage waste through AD, as well as investment in infrastructure. The following recommended policies outlined in this pillar should be considered.
Conclusion
Anaerobic digestion (AD) is an important pathway for managing organic residues generated worldwide. By investing in the necessary infrastructure for waste collection and segregation, governments can successfully transform waste into a valuable resource. This approach not only fosters a circular economy but also benefits communities by promoting sustainable practices.
PILLAR 2: Feedstock Policy
Introduction
Feedstocks are arguably the starting point of the biogas industry. These are the organic materials that are biodegraded in a digester to generate biogas, biofertiliser and bio-CO2. Primary feedstocks for the biogas industry include:
- organic fraction of municipal solid waste (food and garden waste)
- agricultural feedstocks (crop residues, animal slurries and purpose-grown crops)
- domestic sewage
industrial waste and wastewater (such as waste from breweries, slaughterhouses, palm oil mills and the sugar industry).
Most of these feedstocks are not currently captured and used. If they were, anaerobic digestion (AD) provides the opportunity to produce:
- renewable energy, which can be used to replace fossil fuels across power, heat and transport,
- bio-CO2, which can either be utilised in place of its fossil-generated equivalent or stored,
- digestate, a biofertiliser that can improve soil quality and replace nitrogen fertilisers.
By converting organic materials into renewable energy and valuable resources, AD lays the foundation for a sustainable circular economy.
It is estimated that of the 105 billion tonnes of organic waste generated per year, only 2% is recycled. In most countries, the organic fraction of municipal solid waste and industrial waste end up in landfills, causing methane emissions or being burned alongside residual waste in incinerators, resulting in the loss of nutrients and energy. Domestic sewage and industrial wastewater end up in our water bodies with little or no treatment. Animal slurries are stored in open heaps, causing methane emissions, and when applied to land without treatment, they create run-off that pollutes surface and groundwater. Crop residues are sometimes burned, causing significant air pollution.
If they are not captured and managed properly, organic wastes lead to the emission of methane, which is a potent greenhouse gas (GHG) that also poses environmental and health risks. Conversely, through AD, these wastes, along with purpose-grown organic materials, can be used to produce energy, reduce emissions and return nutrients to the soil. These organic materials are, therefore, valuable feedstocks for the biogas industry.
Given the varied sources of these feedstocks and the fact that many are not currently collected, a holistic suite of policies and regulations is required to streamline and incentivise their capture and management through AD, as well as investment in infrastructure. This will minimise the negative effects of these feedstocks and maximise their benefits. The following policies can be considered.
2.1. Establish targets to eliminate organic waste from landfills
Nearly 50% of municipal solid waste is organic, both food and garden waste.1
Figure 1. Global average solid waste composition
* ‘Other’ includes items such as textiles, wood, rubber, leather and household and personal hygiene products.
Any organic waste that ends up in landfills results in methane emissions unless the landfill gas is captured and flared or used. With advances in remote sensing technology, the full extent of methane emissions from dumpsites and uncapped landfills is now being recognised and mapped. Vital agricultural nutrients, such as nitrogen, phosphorus and potassium, are lost or locked up in these landfills for an indefinite period. When not managed properly, organic waste in landfills can leach into water bodies and groundwater, causing water pollution. Animal and bird scavenging of organic waste poses serious health and sanitation risks.
The primary action needed to mitigate these risks is to divert organic waste from landfills to recycling or recovery facilities such as biogas plants. This must be supported by establishing progressive targets for reduction leading to the elimination of organic waste in landfills.
EXAMPLE
South Korea has enforced a ban on landfilling food waste since 2005.2
The EU has a landfill directive in place that obligates countries to implement national strategies to progressively reduce the amount of biodegradable waste sent to landfills.3
2.1.1. Mandatory capping and capture of landfill gas
It is estimated that organic waste in landfills globally accounts for 11% of all anthropogenic methane emissions.4 Policies must be implemented that make the capping of all existing and new landfills mandatory. They must also require the collection and use of landfill gas that is generated to either generate heat and power using a CHP engine or upgrade it to biomethane and used in heating or as transport fuel.
EXAMPLE
British Columbia in Canada has detailed regulations on the management of landfills and landfill gas. It has made covering landfills and capturing landfill gas for use or flaring mandatory.5
2.1.2. Impose landfill and incineration taxes on organic waste disposal
Waste disposal taxes and fees on organic waste sent to landfill or incineration are a widely used policy instrument to encourage recycling. By levying these taxes on the generators of organic waste at the point of disposal, governments can divert organic waste from landfill and incineration to AD and composting by making them financially favourable.
The disposal fee must also be set in a way that continues to incentivise the reduction of waste generation. For this, a tiered approach is recommended, with the highest fee for landfills and incineration and a lower fee for AD, which will also provide a revenue stream for AD facilities.
The level of disposal tax or fee must be considered carefully and increased only gradually. The fee must be high enough to encourage recycling but not too high, as that can result in increased instances of fly-tipping (illegal dumping).
The introduction of such a policy must be tightly linked to the development of separate organic waste collection and AD infrastructure.
EXAMPLE
Twenty-two member states of the European Union have implemented a landfill tax and a tax on incineration.6
2.1.3. Implement pay-as-you-throw systems for waste disposal
In most places, local authorities charge residents and businesses a flat fee based on the size of the home or business, the number of bins provided, or a similar fixed parametre. To incentivise or reward reduction in waste generation, pay-as-you-throw systems must be implemented. A pay-as-you-throw system is based on the principle of ‘the polluter pays’, and local authorities charge customers (residents or businesses) based on the weight of waste they generate.
These pay-as-you-throw systems should, however, only be implemented in countries where very strong waste collection and management systems already exist and must be backed with strict enforcement.
EXAMPLE
South Korea has an advanced pay-as-you-throw system that is based on weight measurements of the waste disposed and radio frequency identification (RFID).7
2.1.4. Establish programmes to monitor and report the quality of water bodies
One of the biggest risks from the discharge of untreated sewage and industrial wastewater and agricultural run-off is the contamination of water bodies, such as rivers, ponds, lakes, groundwater and ocean fronts. This poses a health and safety risk to people, flora and fauna. It is, therefore, critical to monitor the water quality of all water bodies. This also helps to identify and address any trends or instances of deterioration in water quality due to discharge of untreated or insufficiently treated wastewater, or agricultural or industrial run-off.
EXAMPLE
Denmark has an established programme of monitoring the water quality of rivers, streams, lakes and marine waters.8
2.1.5. Consult key stakeholders to develop sector-specific policies
Changing the traditional patterns of organic waste management will affect multiple stakeholders, from farmers to local authorities, waste management companies, businesses creating and using those wastes, and householders having to segregate waste for collection.
The ambition in engaging stakeholders is two-fold:
- To ensure a reliable flow of appropriate waste is available for the development of biogas plants and understanding what those volumes are and from which sectors they will derive.
- To ensure that the policies developed and implemented are practical and achieve the intended results, i.e. sustainable development of the sector and the biogas industry.
EXAMPLE
The Global Methane Initiative has case studies from Bangladesh and Colombia on how governments have engaged with interested parties to implement policies to reduce short-lived climate pollutants.9
2.2. Prioritise biogas generation from waste
One of the key aspects of the AD industry is that it primarily treats organic waste that would otherwise cause climate change, biodiversity loss, and air, water and soil pollution.10 In treating this organic waste, the industry generates energy, organic fertiliser and, if upgraded to biomethane, bio-CO2 while protecting people’s health and the environment.
It is, therefore, important to prioritise and incentivise the treatment of unavoidable organic waste, alongside dedicated energy crops.
EXAMPLES
Biogas plants in the UK were entitled to feed-in tariffs (FIT) on biogas generated from up to 50% of non-waste feedstocks. If the proportion of non-waste feedstock exceeds this 50% threshold, FIT payments were reduced proportionally for the excess.11
Several countries, including Germany, provide higher feed-in tariffs for energy generated from wastes such as manure and biowaste.12
2.2.1. Ensure consistent valorisation of quality feedstocks for anaerobic digestion
Several waste streams must be ring-fenced or prioritised for biogas plants, because the value they bring in terms of renewable energy and environmental benefits outweighs other possible treatment options. These may include sewage sludge, brewery wastes, palm oil mill effluent, domestic and business food waste, and manure. The ring-fenced priority feedstocks must be evaluated regularly to allow for future technology and market development.
2.2.2. Set consistent sustainability criteria for all feedstocks
AD of organic wastes and purpose-grown crops has numerous benefits when done in the right way. While the decarbonisation of energy and the treatment of wastes are key benefits of the biogas industry, there must be minimal unintended consequences on the environment, economy and society. It is, therefore, critical for governments to set sustainability criteria for the industry at large, which may include the following:
2.2.2.1. Greenhouse gas emissions
Based on lifecycle assessments of feedstocks, a maximum greenhouse gas (GHG) emissions threshold should be defined, or minimum emissions reductions over fossil fuel-based energy could be set.
EXAMPLES
To qualify for government financial support in the UK, the lifecycle emissions associated with biomethane produced from biogas must be less than or equal to 24g CO2 eq./MJ of biomethane injected.13
European legislation requires GHG emissions savings of 65–80% from bioenergy, including biogas consumed in the transport sector, over conventional energy generation, depending on the date the installation starts operation.14
2.2.2.2. Proximity
The proximity principle is a key policy approach within waste management. It suggests that waste should be treated or disposed of as close to its source as possible to minimise transport-related emissions and environmental impacts. The use of local, seasonal, and traditional feedstocks is key to the industry’s environmental sustainability, as this considers not only GHG emissions but also the broader sustainability and biodiversity of air, water, and soil. It is, therefore, important to set proximity criteria on feedstocks used for AD.
2.2.2.3. Conservation
The development and operation of AD plants must not have a negative effect on biodiversity, ecosystems, conservation values or carbon stocks. Primary forests, highly biodiverse habitats, protected areas, and habitats such as forests, wetlands and peatlands, must be protected at all costs.
2.2.2.4. Land-use change
Change of land use is associated with the release of carbon stored in the soil, and restrictions on these changes are recommended to support carbon stocks and biodiversity. Land rights must also be respected.
2.2.2.5. Soil
In generating digestate for application to land, long-term soil fertility must be maintained or enhanced in terms of structural stability and organic matter, nutrient cycling, water retention capacity content, and soil temperature.
Soil must also be protected from pollution by microplastics, agrochemicals and trace metals. Soil health and quality must be monitored and reported at farms where the feedstock is generated, and land where digestate is applied.
2.2.2.6. Local food security
The feedstocks for AD must not compromise local and regional food security, i.e. only allowing the digestion of ‘unavoidable’ food waste and loss. Where bioenergy crops are used, they must not affect the price and availability of food for the local population.
2.2.2.7. Water
Biogas plants must be operated and crops grown in a way that maintains or enhances the quality of surface and groundwater resources and does not affect its availability to the local population.
2.2.2.8. Rural and social development
Biogas plants must be built in a way that they contribute to rural and social development. This could be through employing local staff, using local feedstocks, using biofertiliser or digestate locally, and using locally manufactured equipment where possible.
2.2.2.9. Local culture
he local culture must be respected and considered in the establishment and operation of biogas plants. For example, in cultures where cows or pigs are considered holy, digestate from slaughterhouses may be culturally inappropriate.
2.2.2.10. Human and labour rights
Human and labour rights must always be enforced in the development, operation and supply chain of biogas plants.
EXAMPLES
Sustainability criteria for bioenergy production have been developed and enforced by the EU via the Renewable Energy Directive 2018/2001.15 A number of certification schemes have been recognised to verify, audit and maintain chain of custody for criteria, such as the International Sustainability and Carbon Certification and REDcert. 16 17
Wider sustainability criteria have been developed by Roundtable for Sustainable Biomaterials.18 RSB certification is used in the bioethanol, biodiesel, sustainable aviation fuel, bio-based chemicals, and food and beverage industries, among others.
2.2.3. Set quality management standards and regulations for feedstock
The energy content of feedstock determines the amount of biogas generated, and the quality of feedstock determines the quality of digestate produced. If there are impurities such as pathogens, animal or plant diseases, plastics and persistent organic pollutants, or liquid contaminants such as mineral oils and pesticides in the feedstock, these will be transferred to the digestate and the land where it is applied. There must be a clear definition of how waste streams will be treated, define waste quality for compost, AD process or other.
Governments, therefore, must put in place regulations and standards for feedstock quality as well as digestate quality. These are discussed further in Pillar 4: Digestate Policy, Pillar 6: Technical and Operational Quality Standards, and Pillar 7: Environmental Regulations and Permitting. The International AD Certification Scheme Module 4: Process Monitoring and Module 8: Animal By-Product Regulations Compliance provide guidance on operational best practices for feedstocks.
2.2.4. Link access to government support schemes to waste-management hierarchy and sustainability criteria
The waste hierarchy sets the order of preference for waste management – the most preferred option being preventing waste and the last resort sending waste to landfill. AD is considered a waste-recovery technology.19
Figure 2. Waste hierarchy20
Any financial incentive or support provided by the government to biogas plants must be based on evidence of the waste management hierarchy and sustainability criteria being implemented. This will encourage economy-wide adoption of best practices and support both agriculture and industry in the long term.
EXAMPLE
In the Netherlands, the Stimulation of Sustainable Energy Production and Climate Transition (SDE++) scheme links financial incentives for biogas production to RED II and RED III sustainability criteria, and the subsidy calculation is based on tonnes of carbon dioxide reduced.21
Policies like this are applicable to all feedstocks and AD sectors. In addition, certain feedstock-specific policies are needed to streamline the capture and treatment of feedstock streams.
2.3 Food Waste
An IPCC special report estimates that global food loss and waste equalled 8–10% of total anthropogenic GHG emissions and cost about $1 trillion per year.22 It is essential to reduce this food waste, reduce emissions and recover nutrients by treating the unavoidable food waste via AD.
2.3.1. Implement policies to reduce food waste
2.3.1.1. Standardise food date labelling
At the household level, while some date labels on foods refer to food safety (e.g. ‘use by’), others target food quality (e.g. ‘best before’ and ‘display until’). The meanings of these labels are often unclear to consumers and leads to wastage of food that is still safe and edible. Governments can streamline labelling to reduce consumer-level food waste.
EXAMPLE
The UK Charity WRAP has worked with the UK government to developed labelling guidance, aiming to tackle food waste.23
2.3.1.2. Enact Good Samaritan laws
Governments can pass ‘Good Samaritan’ laws that limit the liability of donors in case redistributed food unexpectedly turns out to be somehow harmful to the consumer, unless there has been gross negligence. By providing this legal protection to people and organisations, governments can encourage redistribution of surplus food, thereby reducing food waste.
EXAMPLE
The Bill Emerson Good Samaritan Food Donation Act of 1996 is an example from the US. 24 25
2.3.1.3. Tax credits and tax deductions for food redistribution
Governments can encourage the redistribution and donation of food by giving tax and fiscal incentives or relief, thereby reducing food waste.
EXAMPLES
In Portugal, donors can make use of a tax deduction of up to 140% of the value of food (subject to donation limits) if the food will be used for a social purpose.
In France and Spain, a proportion (35–50%) of the value of donated food can be claimed as corporate tax credit and subtracted from the taxable revenue of the donor enterprise.26
Italy has developed a host of policies to reduce food waste, including a reduction in waste tax for organisations that donate food.27
2.3.1.4. Prioritise animal feed
This step applies to food waste that is inedible for humans but suitable for livestock, such as juice pulp, spent brewers’ grains and whey permeate. The approach to feeding food waste to animals varies between countries. The key to successful redistribution to livestock is food safety and animal health, which can be ensured with heat treatment and a robust certification process.
EXAMPLES
Recycled food waste in Japan is sold as a premium product – ‘eco-feed’ – for livestock consumption. There is a certification scheme in place to ensure safety standards are maintained and ambitious targets for its uptake. 28 29
In the USA, feeding food waste to animals is heavily regulated under federal law, with some states going further and banning the feeding of vegetable waste to pigs. 30 31
2.3.2. Enact legally binding targets for food waste reduction
The reduction of food waste in most countries is largely voluntary and based on economic feasibility. By adopting legally binding targets, governments can strengthen action to reduce food waste, ensuring that the environmental and social costs associated with it are taken into account.
EXAMPLE
The European Parliament voted in March 2024 to create legally binding food waste reduction targets of 20% for processing and manufacturing and 40% for retail, restaurants and households by 2030.32
2.3.3. Introduce a reporting requirement for large food waste generators
Businesses that generate large quantities of food waste, such as food-processing facilities, wholesale food suppliers, grocery stores, restaurants and catering businesses, food services, etc., should be required to report the origin, volume and disposal methods of such waste. This informs policymakers about the sources and volume of food waste and allows businesses to calculate the cost of their waste, thus encouraging its reduction.
EXAMPLE
Ulster County in the US has enacted the Food Waste Prevention and Recovery Act that regulates large generators of food waste. For information purposes, it maintains a mapping tool that provides data on organic waste resources and utilisation pathways.33
2.3.4. Make separate food-waste collections and recycling and recovery mandatory
Collecting food waste from households and businesses separately enables the recovery of energy and nutrients via AD. Commercial establishments generating organic waste in excess of a predetermined threshold may be required to recycle it on-site or, if such a facility exists, within a certain distance, to ensure its proper disposal and the recovery of energy and nutrients. Management of source-segregated food waste requires significant investment in collection and treatment infrastructure and should therefore, be introduced in a phased manner, starting with the most densely populated areas or the largest industries.
EXAMPLES
Mandatory separate food waste collections have been in place in South Korea since 2005 34. In 2022, the government enacted a law that requires large generators of organic waste to generate biogas. Based on the potential of the organic waste generated, the large industries will be required to generate up to 10% of their potential by 2026, increasing to 80% by 2045. Public sector enterprises must produce 50% of their potential by 2025, reaching 80% by 2045. 35
The State of Connecticut in the USA passed the Commercial Organics Recycling Law that requires generators of 26 tonnes or more of source-segregated organic materials located within 20 miles of an authorised composting or AD facility to reduce, donate and make arrangements for AD or composting of the organic waste.36 A map with the address, feedstock capacity and contact details of all authorised facilities in Connecticut has been made publicly available to facilitate the process. 37
2.3.5. Develop and implement best practices in separate food waste collections
Separate food waste collections require an understanding of behavioural science alongside the deployment of collection and treatment infrastructure. When new practices are implemented with behavioural change in mind, the volume of food waste collected will be higher and have fewer contaminants such as plastic films and metal cutlery. It must be noted that best practices will be highly local in nature due to economic, social and cultural differences and must consider these nuances. Overarching best practices include:
- Extensive communication with residents and businesses.
- Clear and consistent signage and awareness campaigns on what can and cannot go in food waste recycling.
- A gradual roll-out of programmes, starting with a trial or pilot and extending to the wider population once it is shown the system functions.
- The provision and use of biodegradable or compostable liners for collections have been associated with higher participation and volumes of collected waste.
- Collecting food waste separately from garden waste, especially if AD is the chosen treatment option.
- Weekly, or more frequent, collection of food waste to prevent odour and rodents.
- Supporting and building capacity to treat separately collected waste via AD.
- Regular and ad hoc visual inspections of food waste bins before collection, followed with penalties and additional awareness campaigns in areas where contamination rates are higher than average.
EXAMPLE
In the UK, WRAP has developed evidence-based separate food waste collection guidelines for households. 38
Best practices and case studies on separate food waste collection and management programmes from across the globe have been published by the World Biogas Association in collaboration with C40 Cities. 39
2.4. Crop residues and purpose-grown crops
Crop residues and purpose-grown crops are key feedstocks for the biogas industry. These are also the off-takers for the digestate that is produced at the end of the digestion process.
2.4.1. Enforce bans on the burning of crop residues and implement policies to encourage their use
Parts of crops that are not commonly consumed by people, such as stalks, roots and leaves, are classified as crop residues. While the roots are normally left in the ground, the remaining residues are ploughed in, fed to animals as fodder or harvested for use as biofuel. Although most countries dissuade farmers from doing so, in some regions this residue is simply burned.
Burning crop residues removes weeds and pests and clears the field quickly to allow the next crop to be sown, but it also results in the loss of nutrients (nitrogen, phosphorus, potassium), the loss of soil organic carbon and the emission of GHGs. It kills microbial flora and fauna, resulting in the deterioration of soil health, and is a fire hazard. Burning also results in the emission of particulate matter and other gases, such as sulphur dioxide, carbon monoxide and volatile organic compounds, that are detrimental to human health. While most countries have made burning crops illegal, the regulation is often not strictly enforced.
To be effective, these bans must be implemented in close coordination with policies, awareness campaigns and support mechanisms that encourage alternative in-situ and ex-situ uses of the residues.
Some examples of residue management solutions are:
- Ploughing into the soil. This is the most common and in-situ method of managing crop residues.
- Use to feed livestock and/or as bedding for livestock when housed during winter months.
- Use as feedstock for biofuel and biogas production.
- Use in agriculture as compost and mulch.
- Convert crop residues into products such as paper, straw board, hats, mats, ropes, baskets and packaging.40
EXAMPLES
Through comprehensive and long-term policy and technology support, India has been able to significantly reduce instances of crop burning in the states of Punjab and Haryana. These include: passing laws banning the practice of burning crop residues as a deterrent; creating awareness and capacity-building; providing financial assistance; use of advanced machinery; imposing penalties; and implementing pilot projects. 41
Cambodia has implemented a ban on the burning of rice straw. 42
2.4.2. Implement a price-support mechanism for crop residue
A key element of making use of crop residues is the ability of farmers to monetise them in the long term. By setting a minimum price and a price-support mechanism for crop residues, particularly in countries with majority small farms, governments can make the collection and use of crop residues financially viable for farmers who may otherwise choose to burn the crop residue.
However, the mechanism must be set in a way that does not disincentivise other productive uses, such as animal feed and bedding.
2.4.3. Encourage cooperative models for small farms
Where a farm is small and therefore not suitable for an individual contract with a biogas plant or the development of one on-site, aggregation of residues may be needed.
Governments can facilitate long-term contracts between farmers with crop residues, feedstock aggregators and biogas plant developers and operators. If the farm rears livestock, manure can be included in this supply chain. In doing so, governments can ensure that farmers get a fair price for the residues and are incentivised not to burn them. AD operators would, in turn, get access to a steady and assured supply of feedstock that, via digestion, can generate both economic and environmental benefits. This may need to be facilitated through cooperative societies, self-help groups, registered farmers societies, farmer producer organisations, or village, district, or local government.
EXAMPLE
Under the Gobardhan Programme, the Indian government has developed interventions for crop residue management in the states of Punjab, Haryana, Uttar Pradesh, Madhya Pradesh and Delhi. These include the development of a crop residue supply chain through a cluster-based approach near industries where they can be used. 43
2.4.4. Build digestate off-take into crop residue contracts, where possible
It is recommended that digestate off-take is built into crop residue feedstock contracts. This will ensure an economic and environmentally symbiotic relationship between farmers and biogas operators. It will also ensure that the benefits of AD and the circular economy are maximised on the farm and in the local area.
EXAMPLE
In Italy, implementing the BiogasDoneRight concept, digestate use is incorporated into the farming model to improve soil quality, offset chemical fertiliser use and increase yields of crops. Detailed case studies from a farm in Po Valley and Enna Farm in Sicily are available. 44
2.4.5. Establish and enforce best practices for bioenergy crop production
Crops that are grown for the sole purpose of producing energy are known as bioenergy crops. These energy crops, such as maize, beet, grasses and rye, are generally considered to be low-carbon, renewable sources of energy. They substitute the energy that would have otherwise been produced from fossil fuels and can repeatedly be renewed through growing new crops.
They are added to low-energy-waste feedstocks like livestock manure to increase the energy production from biogas plants. Good practice in the choice and cultivation of energy crops can bring positive environmental outcomes and avoid risks, in particular by integrating crops for AD into the whole farm system.
Sustainability criteria for all feedstocks, including bioenergy crops, are laid out earlier in this Pillar (section 2.2.2). To meet those sustainability criteria, site- and crop-specific measures must be implemented. Some basic guiding principles of bioenergy crop production are:
- Restrict land-use change to protect carbon stock and environmental resilience.
- Avoid cultivation on areas of high biodiversity value marginal lands and permanent grassland where it will have a negative impact on biodiversity.
- Prioritise use of poor and marginal land that cannot be used for food production.
- When selecting a crop as a feedstock for AD, take into consideration environmental factors, including topography, soil type and soil conditions, the climate, and crop cycles with consideration to the lifespan of the project.
- Grow energy crops as break crops or as part of rotational cropping.
- Grow cover crops for the protection of soil over winter and enhance nutrition in in the soil, including nitrate and carbon sequestration.
- Consider pest and disease transfer and persistence of the entire farm.
- Establish ecological focus areas (EFAs) on 5% of the arable area of the holding by use of hedgerows, fallow land, buffer strips, nitrogen-fixing crops, catch crops, and/or green cover.
- Apply digestate to crops based on their nutrient requirements and stage of growth, using distribution systems that maximise uptake, minimise run-off and avoid soil compaction.
- Implement a range of soil-management practices, such as minimum tillage, direct drilling, strip tilling and controlled-traffic farming.
- Adopt more efficient and water-saving watering techniques, such as drip irrigation and pivot irrigation.
EXAMPLE
The Italian Consortium of Biogas (CIB) has developed principles of agricultural sustainability for the biogas industry: BiogasDoneRight. 45
Similar guiding principles have been developed by the Anaerobic Digestion and Bioresources Association (ADBA) in partnership with the government and key stakeholders. 46
2.5 Livestock manure
The Food And Agriculture Organisation (FAO) estimates the global livestock population in 2022 at 1.5bn cattle, 26.5bn chickens, 1.3bn sheep, 1. 1bn goats, 1bn swine/pigs, 200m buffaloes, 60m horses and 40m camels. 47 All of these livestock generate manure that, if not managed properly, leads to methane emissions and leaching of nutrients such as nitrates and phosphorus into nearby waterways and groundwater. 48 Livestock and manure emissions account for nearly two-thirds of emissions from agriculture as shown figure 3. 49
Figure 3: Global GHG emissions by sector
2.5.1. Require the development of nutrient management plans for farms with livestock
A nutrient management plan is a detailed strategy on how nutrients in the form of manure, digestate or chemical fertiliser will be applied on-farm in a way that maximises their use and minimises their environmental impact. This is based on the principles of:
- comprehensive assessment of site-specific land and crop needs
- identification of the right source, method, rate and timing of nutrient application.
The requirement for livestock farms to have such a plan, along with training, can improve nutrient use efficiency and farm profitability, as well as enhancing soil quality and reducing emissions and water pollution.
EXAMPLES
In the UK, the agricultural industry with support from the government has created detailed guidance and a template for creating a nutrient management plan. 50
In the US, all concentrated animal feeding operations must develop a nutrient management plan. 51 Both the US Environmental Protection Agency and the Department of Agriculture provide training, guidance and assistance in SMART nutrient management planning. 52
2.5.2. Incentivise manure management via anaerobic digestion
AD is recognised as the most effective means available for managing methane emissions from manure. 53 It is, therefore, recommended that farmers are encouraged and incentivised to treat manure via AD through preferential treatment and financial incentives.
2.5.3. Make the regulation of manure and digestate consistent
In most cases, livestock manure is stored on-farm and applied to the land without any treatment. While in open storage, manure emits gases, including methane. When applied to land without being adequately stabilised, manure continues to emit GHGs while also affecting the soil characteristics. Untreated manure is also more susceptible to nitrogen and phosphorus run-off, causing eutrophication of water bodies.
It is, therefore, important to safeguard the environment by regulating the application of both manure and digestate. Regulation of digestate is discussed further in Pillar 4: Digestate Policy.
2.5.4. Provide financial assistance for construction and maintenance of microscale biogas plants
Given the wide-ranging benefits of the digestion of manure in rural communities, support must be provided towards the construction and maintenance of microscale biogas plants.
EXAMPLES
The biogas programme in India provides financial support for microdigesters that use animal manure as feedstock. 54
In China, the central and provincial governments, along with rural households, co-funded the construction of 32m biogas plants via the Development and Promotion of Biogas Utilisation in Rural China programme. It also supported training in rural biogas design and planning; construction and management; biogas production safety; product quality standards; and comprehensive use. 55
2.6 Domestic wastewater (sewage)
Sewage from human wastewater is a steady and readily available feedstock, where sewage systems are installed. Its treatment via AD has several benefits, including energy and nutrient recovery, protecting water bodies from pollution, and reducing the spread of water-borne diseases.
However, it is estimated that just 58% of global domestic wastewater is collected, delivered to treatment and safely treated and discharged. 56 It is, therefore, critical to ensure the collection and treatment of sewage before it is discharged to water bodies. Policies specific to domestic wastewater follow.
2.6.1. Invest in wastewater collection and treatment via anaerobic digestion
Sewage collection and treatment is part of the basic sanitation infrastructure that every country provides for its population. The waste stream is ubiquitous, non-seasonal, abundant and homogeneous, and wastewater facilities, especially in cities, are of a size to make both the investments manageable and the volumes of biogas produced a valuable market asset. Treatment of this sewage through AD, in conjunction with other physical, chemical and biological processes, is very well established and implemented across the world. 57 It is estimated that energy recovered from AD can offset 50–60% of the energy demand of a wastewater treatment plant. 58 Policy should prioritise investment in biogas plants for energy and nutrient recovery.
EXAMPLES
Of the 2,400 biogas plants operating in the US in 2019, nearly half (1,120) were wastewater resource recovery facilities or wastewater treatment plants 59.
Many European countries, including Germany, Norway, Sweden, Switzerland and the UK, have wastewater treatment plants that recover energy from sewage sludge. 60
2.6.2. Provide support to microdigesters for the decentralised treatment of domestic sewage
In remote and rural areas where sewage infrastructure is not yet feasible, microscale digesters can provide a decentralised solution for sanitation and waste management. 61 Areas not served by sewage collection infrastructure must be mapped and special policies and incentives introduced to support treatment via microscale AD.
EXAMPLES
By 2015, Nepal’s domestic biogas programme had installed approximately 350,000 domestic biogas units, and of these up to 79% had a connected toilet. 62
The biogas programme in India provides additional financial support for microdigesters that are linked to toilets. 63
2.7. Industrial waste and wastewater
The industrial waste and wastewater generated by countries is wide ranging and based on their local economies. Some industries generate organic waste, residues or wastewater that has high organic carbon loading, such as those from: palm oil mills in Indonesia and Malaysia; meat processing in the US; bagasse and vinasse in Brazil; fish processing in Japan; the brewing industry in Germany and distilleries in Scotland; the pulp and paper industry in Canada; cheese and wine industries in France; olive oil and tomatoes in Italy; cassava processing in Nigeria; and rice processing in Vietnam.
If wastewater with organic loading is released into water bodies without adequate treatment, it depletes the oxygen in the water, thereby harming the aquatic flora and fauna. These wastes are particularly suitable for implementing AD, as the organic matter drives the biogas production.
2.7.1. Identify and engage with industries and trade groups and associations
The impact of industries on the national economy, energy use and emissions can be significant. Identifying and engaging with industries that generate high volumes of organic residues and wastewater is important to manage their effect on all three areas and drive energy self-sufficiency.
This engagement is necessary for the development and implementation of environmental regulations for industries and the growth of the biogas industry.
EXAMPLE
Indonesia is the world’s largest producer and exporter of palm oil and the fourth largest producer of tapioca. The two industries combined have a potential to generate 1.25 GWe of electricity, but only 0.15 GWe is currently installed. 64
2.7.2. Establish and enforce environmental permitting regulations
Establishing and enforcing limits on what can be discharged into water bodies via environmental permitting will lead to more widespread adoption of AD technology for the treatment of industrial wastewater.
This is a commonly used mechanism for environmental protection and is discussed further in Pillar 7: Environmental Regulations and Permitting.
EXAMPLE
In the USA, the Clean Water Act sets technology- and water-quality-based effluent limits. These are enforced via environmental permits and robust monitoring. Exceedances are managed via fines, penalties and mandatory corrective measures. 65
2.8 Looking forward
What goes in, comes out. Feedstocks are the starting point of the AD industry. With the world currently recycling only 2% of the 105bn tonnes of organic waste it generates every year, the industry has a huge potential to grow and affect the world around it. With the right policies in place, there is potential to streamline the flow of feedstocks to the industry and realise its potential to mitigate climate change, replace fossil fuels, improve soil quality and productivity, and improve health and sanitation.
Footnotes
- Map of Global Waste Methane Emissions, Wastemap. https://wastemap.earth/map
- Lee, E., Shurson, G., Oh, S.-H., Jang, J.-C. ‘The Management of Food Waste Recycling for a Sustainable Future: A Case Study on South Korea’. Sustainability. 2024, 16, 854. https://doi.org/10.3390/su16020854
- Landfill Waste Directive, European Commission. https://environment.ec.europa.eu/topics/waste-and-recycling/landfill-waste_en
- Landfill Methane, Global Methane Initiative. https://www.globalmethane.org/documents/landfill_fs_eng.pdf
- Landfill Gas Management Regulation, Environmental Management Act, British Columbia, Canada. https://www.bclaws.gov.bc.ca/civix/document/id/complete/statreg/391_2008
- “Economic Instruments and Separate Collection Systems: Key Strategies To Increase Recycling”, European Environment Agency. https://www.eea.europa.eu/publications/economic-instruments-and-separate-collection
- Lee, E., Shurson, G., Oh, S.-H., Jang, J.-C. ‘The Management of Food Waste Recycling for a Sustainable Future: A Case Study on South Korea’. Sustainability. 2024, 16, 854. https://doi.org/10.3390/su16020854
- “Surface Water Quality Monitoring: Summary: Denmark”, European Environment Agency. https://www.eea.europa.eu/publications/92-9167-001-4/page006.html
- “Engaging Stakeholders”, Global Methane Initiative. https://globalmethane.org/pmf/Step2
- “Beyond an Age of Waste”, UNEP. https://wedocs.unep.org/bitstream/handle/20.500.11822/44939/global_waste_management_outlook_2024.pdf
- “Feed-in Tarifs”, Ofgem. https://www.ofgem.gov.uk/sites/default/files/docs/2018/06/sustainability_and_feedstock_guidance_version_2.pdf
- Premium Tariff (Market Premium), RES LEGAL Europe. http://www.res-legal.eu/search-by-country/germany/single/s/res-e/t/promotion/aid/premium-tariff-i-market-premium/
- Sustainability Requirements, Green Gas Support Scheme Guidance, Ofgem. https://www.ofgem.gov.uk/sites/default/files/2022-10/GGSS_Guidance_v1.2.pdf#page=112
- “Promotion of the Use of Energy From Renewable Sources”, European Union. http://data.europa.eu/eli/dir/2018/2001/oj
- Directive (EU) 2018/2001, European Union. http://data.europa.eu/eli/dir/2018/2001/oj
- Sustainability Requirements, ISCC. https://www.iscc-system.org/wp-content/uploads/2022/05/ISCC_202_Sustainability_Requirements_3.1.pdf
- REDcert sustainability certification. https://www.redcert.org/en/
- “RSB Principles and Criteria. https://rsb.org/wp-content/uploads/2024/05/rsb-principles-criteria-std-01-001-v4-1.pdf
- Waste Framework Directive, European Commission. https://environment.ec.europa.eu/topics/waste-and-recycling/waste-framework-directive_en
- Waste Framework Directive, European Commission. https://environment.ec.europa.eu/topics/waste-and-recycling/waste-framework-directive_en
- SDE++ 2023: Stimulation of Sustainable Energy Production and Climate Transition, Government of the Netherlands. https://english.rvo.nl/sites/default/files/2023-09/BrochureSDE2023English.pdf
- Food Security, IPCC. https://www.ipcc.ch/srccl/chapter/chapter-5/
- Labelling Guidance, WRAP. https://www.wrap.ngo/sites/default/files/2020-07/WRAP-Food-labelling-guidance.pdf
- Public Law 104-210, 104th Congress. https://www.govinfo.gov/content/pkg/PLAW-104publ210/pdf/PLAW-104publ210.pdf
- “Good Samaritan Act Provides Liability Protection For Food Donations”, US Department of Agriculture. https://www.usda.gov/media/blog/2020/08/13/good-samaritan-act-provides-liability-protection-food-donations
- “Financial Rules on Food Donation”, European Commission. https://food.ec.europa.eu/document/download/b915c933-3cbe-4d8b-8b5a-df86417bfc84_en?filename=fw_factsheet_fd_financial-rules_en.pdf
- “Italy’s Law for Donation and Distribution of Food And Pharmaceuticals To Limit Food Waste”, Zero Waste Europe. https://zerowasteeurope.eu/wp-content/uploads/2020/11/zwe_11_2020_factsheet_italy_en.pdf
- FFTC Agricultural Policy Platform (FFTC-AP). https://ap.fftc.org.tw/article/2794
- Sugiura, K., Yamatani, S., Watahara, M., Onodera, T. (2009) ‘Ecofeed, Animal Feed Produced from Recycled Food Waste’, Veterinaria Italiana, 2009, 45(3), 397–404. http://www.izs.it/vet_italiana/2009/45_3/397.pdf
- “Leftovers for livestock: A Legal Guide for Using Food Scraps as Animal Feed”, Harvard Food Law and Policy Clinic and the Food recovery Project University of Arkansas, School of Law. https://www.chlpi.org//wp-content/uploads/2013/12/Leftovers-for-Livestock_A-Legal-Guide_August-2016.pdf
- ReFED US Food Waste Policy Finder. https://policyfinder.refed.org/
- “MEPs Call for Tougher EU Rules To Reduce Textiles and Food Waste”, European Parliament News. https://www.europarl.europa.eu/news/en/press-room/20240308IPR19011/meps-call-for-tougher-eu-rules-to-reduce-textiles-and-food-waste
- “Food Waste Prevention and Recovery Act”, Ulster County, State of New York. https://ulstercountyny.gov/environment/food-waste-prevention-and-recovery-act
- https://www.undp.org/sites/g/files/zskgke326/files/migration/seoul_policy_center/USPC-Policy-Brief-3.pdf
- National Law Information Center. Promotion of Biogas Production and Utilization from Organic Waste Resources (Notice No. 19151). 2022b. Available online: https://www.law.go.kr/%EB%B2%95%EB%A0%B9/%EC%9C%A0%EA%B8%B0%EC%84%B1%ED%8F%90%EC%9E%90%EC%9B%90%EC%9D%84%ED%99%9C%EC%9A%A9%ED%95%9C%EB%B0%94%EC%9D%B4%EC%98%A4%EA%B0%80%EC%8A%A4%EC%9D%98%EC%83%9D%EC%82%B0%EB%B0%8F%EC%9D%B4%EC%9A%A9%EC%B4%89%EC%A7%84%EB%B2%95/(19151,20221230)
- Commercial Organics Recycling Law, Department of Energy & Environmental Protection, Connecticut. https://portal.ct.gov/deep/waste-management-and-disposal/organics-recycling/commercial-organics-recycling-law
- Food Waste Composting Facilities, Department of Energy & Environmental Protection, Connecticut. https://portal.ct.gov/deep/waste-management-and-disposal/organics-recycling/food-residual-composting-facilities
- “Household Food Waste Collections Guide”, WRAP. https://www.wrap.ngo/sites/default/files/2024-02/WRAP-Household-Food-Waste-Collections-Guide-V17.pdf
- “Global Food Waste Management: An Implementation Guide for Cities”, WBA. https://www.worldbiogasassociation.org/wp-content/uploads/2018/05/Global-Food-Waste-Management-Full-report-pdf.pdf
- “Paddy Straw Trays: How Did the Iconic Food Become Packaging?”, TIPA. https://tipa-corp.com/blog/paddy-straw-trays-how-did-the-iconic-food-become-packaging/
- Dutta, A., Patra, A., Hazra, K.K., Nath, C.P., Kumar, N., Rakshit, A. “A State of the Art Review in Crop Residue Burning in India: Previous Knowledge, Present Circumstances and Future Strategies”, Environmental Challenges, 2022, 8, 100581. https://doi.org/10.1016/j.envc.2022.100581.
- “Cambodia Bans Burning of Rice Straw, Garbage To Reduce Air Pollution”, Xinhuanet. http://www.xinhuanet.com/english/2020-12/14/c_139588788.htm
- “Crop Residue Management”, Government of India. https://gobardhan.co.in/assets/guidelines/Crop_Residue_Management_Guidelines_2023-24.pdf
- Anaerobic Digestion and Soil Carbon Sequestration”, BioGasDoneRight. https://www.consorziobiogas.it/wp-content/uploads/2017/05/Biogasdoneright-No-VEC-Web.pdf
- Anaerobic Digestion and Soil Carbon Sequestration”, BioGasDoneRight. https://www.consorziobiogas.it/wp-content/uploads/2017/05/Biogasdoneright-No-VEC-Web.pdf
- Guidance on Sustainable Bioenergy Crops, ADBA. https://adbioresources.org/resources/guidance-on-sustainable-bioenergy-crops/
- Crops and Livestock Products, Food and Agriculture Organization of the United Nations. https://www.fao.org/faostat/en/#data/QCL
- “Livestock and environment Statistics: Manure and Greenhouse Gas Emissions”, Food and Agriculture Organization of the United Nations. https://openknowledge.fao.org/server/api/core/bitstreams/f0cebfdd-725e-4d7a-8e14-3ba8fb1486a7/content
- “Sector by Sector: Where do Global Greenhouse Gas Emissions Come From?”, Our World in Data. https://ourworldindata.org/ghg-emissions-by-sector
- “Nutrient Management Plan”, Tried and Tested. https://www.triedandtested.org.uk/media/h1nptq5k/nfu-nutrient-management-plans-booklet-a4-20pp_web.pdf
- “Understanding Nutrient Management Plans”, US EPA. https://www.epa.gov/npdes/understanding-nutrient-management-plans
- “SMART Nutrient Management”, US Department of Agriculture. https://www.nrcs.usda.gov/sites/default/files/2024-02/SMART%20Nutrient%20Mgmt%20farmersgov%20factsheet%202022.pdf
- ‘Practices to Remove Methane Emissions from Livestock Manure Management”, US EPA. https://www.epa.gov/agstar/practices-reduce-methane-emissions-livestock-manure-management
- Biogas Programme (Phase 1), Ministry of New and Renewable Energy, Government of India. https://biogas.mnre.gov.in/about-the-programmes
- “One Digester Plus Three Renovations: Biogas Plants for Rural China”, UNDP. https://www.undp.org/sites/g/files/zskgke326/files/migration/asia_pacific_rbap/EE-2012-Case5-DPBURC.pdf
- “Progress on the proportion of domestic and industrial wastewater flows safely treated – Mid-term status of SDG Indicator 6.3.1 and acceleration needs, with a special focus on climate change, wastewater reuse and health”, WHO, 2024.https://www.who.int/publications/b/75389
- “Sustainable Biogas Production in Municipal Wastewater Treatment Plants”, IEA Bioenergy. https://task37.ieabioenergy.com/wp-content/uploads/sites/32/2022/02/Wastewater_biogas_grey_web-1.pdf
- Chrispim, M., Scholz, M., Nolasco, M. “Biogas Recovery for Sustainable Cities: A Critical Review of Enhancement Techniques and Key Local Conditions for Implementation”, Sustainable Cities and Society, 2021, 72, 103033. https://doi.org/10.1016/j.scs.2021.103033.
- Biogas Market Snapshot, American Biogas Council. https://americanbiogascouncil.org/biogas-market-snapshot/
- “A Perspective on the State of the Biogas Industry from Selected Member Countries”, IEA Bioenergy Task 37. https://www.ieabioenergy.com/wp-content/uploads/2022/03/IEA_T37_CountryReportSummary_2021.pdf
- “Flush toilet with Biogas Reactor ad Offsite Treatment”, World Health Organization. https://cdn.who.int/media/docs/default-source/wash-documents/sanitation/sanitation-system-fact-sheets/fact-sheet-6—flush-(or-urine-diverting-flush)-toilet-with-biogas-reactor-and-offsite-treatmen.pdf
- Williams, N.B, Quilliam, R.S., Campbell, B., Ghatani, R., Dickie, J. “Taboos, Toilets and Biogas: Socio-Technical Pathways to Acceptance of a Sustainable Household Technology”. Energy Research & Social Science, 2022, 86,102448. https://doi.org/10.1016/j.erss.2021.102448.
- Biogas Programme (Phase 1), Ministry of New and Renewable Energy, Government of India. https://biogas.mnre.gov.in/about-the-programmes
- “Market Report: Indonesia”, WBA. https://www.worldbiogasassociation.org/market-report-indonesia/
- “Permit Levels: TBELs and WQBELs, US EPA. https://www.epa.gov/npdes/permit-limits-tbels-and-wqbels
